Technical Field
This invention relates to a device and method for deterring theft of fuel from a fuel tank Specifically, the invention relates to a fill-pipe anti-siphon device and method of use.
State of the Art
The trucking industry generates approximately $650 billion of annual revenue and is responsible for over 80% of all commercial transportation based on revenue generated. There are around two million semi tractor-trailer trucks registered in the United States. A typical truck travels between 45,000 and 100,000 miles annually, depending on whether the unit's usage is regional or “long haul.” Therefore, any commonly occurring condition which renders a semi-truck tractor inoperable can have a substantial economic impact.
Additionally, the theft of diesel by siphoning from semi-truck fuel tanks is widespread. Trucks parked at a truck stop, a motel, restaurant, or loading yard are prime targets for diesel thieves. Anti-siphon devices are available, but are inconvenient to use and have limitations. Locking fuel caps require a key which may be damaged or lost. Barrier devices are typically fitted with flanges that expand on insertion and permanently catch on the inside of the tank preventing removal of the device. Poorly designed barrier devices may also impede the flow of fuel from high-flow fueling pumps present at truck stops, causing spills of fuel foaming up around the fill nozzle.
A common example of a condition rendering a truck temporarily inoperable is fuel leaking from damaged threads on the fuel tank's fill-pipe neck. A standard rig has two side-mounted liquid fuel tanks, each with a capacity of approximately 150 gallons. Each tank has a fill pipe and is sealed by a threaded cap screwed onto the end of the fill pipe neck. After filling the tank with fuel, the operator must securely screw the threaded cap onto the fill pipe neck. If the cap is not properly and tightly secured, engine vibration tends to loosen the connection between the tank cap and the fill pipe neck. Continued vibration between these loosened components wears the tank cap threads against the fill pipe threads, damaging the fill pipe threads. After enough thread wear, the tank cap can no longer be sufficiently tightened on the damaged threads of the fill pipe neck to prevent leakage of fuel from the tank. Leaking fuel creates a characteristic streak of grime, leaving a “leak trial” down the side of the tank and calling the situation to the attention of inspectors who will “red tag” the truck, removing it from the highway until the leaking fill pipe is repaired.
Repairing a leaking fill pipe generally requires replacing the entire fuel tank. This can take from several hours to days, depending on the availability of parts and services at the rig's location. The cost of a new aluminum diesel fuel tank alone is typically between $500 and $1,000. This cost does not include labor or account for lost revenue and other collateral losses arising from the rig's down-time while the tank is replaced. The total costs, therefore, for a single leaking fill pipe can exceed $2,000.
Accordingly, a device is needed to create a durable repair of a leaking tank fill pipe while impeding theft of fuel from the tank by siphoning.